The present invention relations to a pallet container for liquids which can be used to store, move and transport liquids, even of a corrosive nature.
These pallet containers are composed of an inner plastic container, equipped with a filler and a drain tap, both with a hermetic seal, resting on a metal pallet and protected by a metal sheath produced in the form of a cage or plate.
The pallet to be moved by lifting means is composed of a stamped metal plate tray and a plurality of corner and central feet, welded or screwed to a base ring and to the tray, which distance the inner container from the ground, to allow the lifting means to operate.
An alternative proposed in the past, but which did not have great success due to the extremely high loads to which the tray was subjected, proposed production of the pallet in a single piece in stamped plastic material.
The bottom of the inner plastic container and the metal tray is equipped with a drainage channel, which extends sloping downwardly from the rear wall to the front wall to convey the liquid towards the tap.
The central foot is appropriately shaped corresponding to the tap in order not to hinder access to the tap during draining operations.
To improve the load capacity, a reinforcing plate may be fitted under the tray, positioned transversally in relation to the drainage channel. A similar function is performed by the stiffening grooves stamped on the bottom of the tray.
Alternatively to being fixed with screws or welded, the shaped central foot and the central feet in the vicinity of the reinforcing plate are frequently cast integrally to the tray and reinforcing plate respectively.
The main problems concern operations to cast the metal plate to obtain pieces with a transversal section provided with a considerable difference in height. The tray comprising the shaped central foot and the transversal reinforcing plate, from which two side feet are shaped, are pieces that require several subsequent casting operations. The dies required for these operations must take account with extreme precision of the shrinkage of the metal plate. Therefore, the design and production of dies are just as costly as the operations to cast the pieces.
If the metal plate casting operations are not performed optimally, this would cause considerable reduction in the resistance of the pallet to static and dynamic stresses. During transportation the pallet is subjected to bending fatigue stress, caused by oscillation of the masses of liquids transported and drive oscillations transmitted by the vehicle.
Moreover, the pallet containers for liquids, especially if used to transport corrosive liquids, must be dismantled and recycled at the end of their period of use. In fact, for example, the shaped central foot positioned corresponding to the drain tap is greatly subjected to corrosion.
The pallet containers described require laborious dismantling operations to unscrew or separate the weld points and proceed with the recycling of the metal.
The object of the present invention is to produce a pallet container for liquids that attains an excellent level of stability and resistance to applied loads, which influences the safety of transport.
Another object of the present invention is to produce a pallet container for liquids produced with a simple production and recycling cycle.
Yet another object of the present invention is to produce a particularly simple and functional pallet container for liquids with reduced costs.
These objects according to the invention are attained by producing a pallet container for liquids as set forth in claim 1.
Further characteristics are provided for in the subordinate claims.